Patent GB-793136-A (GB)
Title: Improvements in the production of mono- and dis-azo dyestuffs containing chromium
Filed: 1956-02-29
Abstract: Chromium - containing o : o1 - dihydroxy - azo dyestuffs which contain two identical or different dyestuff molecules for each chromium atom are prepared by treating an o-alkoxy-o1-hydroxy-azo dyestuff or a mixture of two or more dyestuffs of the said kind at an elevated temperature and in the presence of an organic solvent, with compounds of hexavalent chromium and with reduction of the chromium compounds.  A solvent having a reducing action on the chromium compounds is preferably used.  Specified solvents are mono- and polyhydric alcohols and their esters and ethers, dioxan tetrahydrofuran, butyrolactone, ethanolamine and carboxylic acid amides.  Substances which may be used to reduce the chromium compounds are salts and esters of sulphurous, thiosulphuric or arsenious acids and mono- and di-saccharides.  Specified compounds of bevalent chromium are alkali metal mono- and dichromates.  In an example the dyestuff 1-amino - 2 - methoxy - 5 - methyl - benzene - 4 - sulphonamide --> 1 - phenyl - 3 - methyl - 5 - pyrazolone is mixed with b  : b 1-dihydroxyethyl ether and sodium chromate, heated, diluted with water and the chromium complex salted out.  Azo dyestuffs prepared from the following components are treated in a similar manner to give their chromium complexes: diazo components: 1 - amino - 2 - methoxybenzene, 1 - amino - 2 - methoxy - 5 - chloro - or - methyl - benzene, 1 - amino - 2 - methoxy - 4 - or - 5 - nitrobenzene, 1 - amino - 2 - methoxy - 4 - nitro - 5 - chloro - benzene, 1 - amino - 2:4 - or - 2:5 - dimethoxybenzene, 1 - amino - 2:5 - diethoxybenzene, 1 - amino - 2 - methoxy - 4 - chloro - 5 - methylbenzene, 1-amino-2:4- or -2:5-dimethoxy - 4 - chlorobenzene, 1 - amino - 2 - methoxy - 4 - phenylamino - benzene, 1 - amino - 2 - methoxybenzene - 5 - carbonamide or -sulphonamide or -sulphomethylamide or -sulphophenylamide or -sulphodiethylamide or -sulpho-(31- or 41-sulphonamido-phenyl)-amide or -methyl or -benzyl sulphone, 1-amino-2-methoxy-5-methylbenzene-4-sulphonamide or -sulphomethylamide or -sulphophenylamide or -sulpho-N-ethyl-N-(21-hydroxy)-ethyl-amide or -methyl sulphone, 1 - amino - 2 - methoxy - 5 - chlorobenzene - 4 - ethylsulphone or-sulphonamide or -sulphomethylamide or -sulphophenylamide, 1-amino-2:5 - dimethoxy - 4 - benzoylaminobenzene, 1 - amino - 2:5 - diethoxy - 4 - acetylaminobenzene, 1 - amino - 2:5 - dimethoxybenzene - 4 - sulphonamide or -sulphomethylamide or -methyl sulphone, 1-amino-2:5-diethoxybenzene - 4 - sulphonamide or -sulphophenylamide, 1 - amino - 2 - ethoxy - naphthalene, 1 - amino - 2 - methoxy - 4 - (41 - sulphonamido - phenylazo) - 5 - methylbenzene and 1 - amino - 2:5 - dimethoxy - 4 - (31 - sulphonamido - phenylazo)-benzene; coupling components:-4 -methyl- or -acetylamino- or -isobutylphenol, 2:4-dichlorophenol, 2-naphthol, 2-naphthol-6-sulphonamide or -sulphophenylamide or -sulpho-N-(21-hydroxy)-ethylamide or -sulphodimethylamide or -sulpho-N-methyl-N-(21-hydroxy)-ethylamide, 2-naphthol-4-sulphonamide or -sulphomethylamide or -sulphophenylamide, 2-naphthol-7-sulphonamide, 2-naphthol-5-sulphomethylamide, 1-naphthol-3- or -4-sulphonamide, 1-naphthol-3:6-disulphonamide or -disulphomethylamide, 2-naphthol-3:6-disulphonamide, 6-bromo-2-naphthol, 5:8-dichloro-1-naphthol, 8-acetylamino- or -carbomethoxyamino-2-naphthol, 1-phenyl- or -(21-methylphenyl)- or -(31- or 41-sulphamidophenyl)- or -(41-methyl-31-sulphamidophenyl)- or -(31- or 41-methylsulphonylphenyl)- or -(21-chloro-51-sulphonamidophenyl)-or -(21:51-dichlorophenyl)- or -(31-chloro- or - nitro - phenyl) - or - (41 - benzenesulphaminophenyl) - 3 - methyl - 5 - pyrazolone, 1 - phenyl - 3-carboethoxy- or -carbonamido-5-pyrazolone, 3 - methyl - 5 - pyrazolone, 1:3 - diphenyl - 5 - pyrazolone, 2:4 - dihydroxyquinoline and 1 - methyl - 4 - hydroxy - quinolone (2).  Specification 758,016 is referred to.